Configuration of MODBUS TCP/IP Configuration

As of Automation_Builder 1.1 (CBP 2.4.) MODBUS configuration has been moved to another location within the device tree. Note: Principle of MODBUS configuration remains unchanged.

Configuration up to CBP 2.4

Double-click on MODBUS_on_TCP_IP (MODBUS on TCP/IP) and select the tab MODBUS on TCP/IP Configuration to show the available MODBUS settings in the editor window:

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Configuration as of CBP 2.4

For MODBUS TCP/IP protocol configuration double-click the MODBUS item in the device tree and select the tab MODBUS TCP/IP Server Configuration:

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Parameters

Depending on the Automation_Builder/CBP version some or all parameters are available:

Parameter Default Value Meaning
Server connections 0

0…X

(X depending on PLC)

Maximum number of logical parallel connections, that are kept for connection requests by clients in operation mode as server. The value 0 means pure client mode (MODBUS master) (0..X, depending on the performance of the PLC)
Task timeout 2000 100 … 6000000 Only valid for client mode. A request is canceled when no response by the server is received within this time in [ms]. (100..6000000 ms)
OMB time 1000 100 … 6000000 Only valid for server mode. Determining how long a logical connection in [ms] remains after receiving the reply message of a client. Establishing and terminating of connection takes some time. When the data communication between the controller and the servers should take place only at long intervals, it is useful to close the connection immediately after completion of the data communication. (100..6000000 ms)
Send timeout 0 0 … 2000000000 Only valid for client mode. Determining how long the controller should try to send a request to a server. (0..2000000000 ms)
Connect timeout 0 0 … 2000000000 Only valid for client mode. Determining how long the controller should try to create a TCP connection with a server. (0..2000000000 ms)
Close timeout 0 0 … 2000000000 Only valid for client mode. Determining how long the controller should try to close a TCP connection with a server. (0..2000000000 ms)
Byte order Big endian Little endian Valid for client and server mode. Format of the transfer of word values (registers) in the telegram. Depending on the settings, the byte order will be changed by sending and receiving. Changing the byte order may be required e.g. when devices with different processor types are used.
Big endian